Probing device for microcircuits

ABSTRACT

A table supporting a three dimensional movement probe mounted on roller bearings for two dimensional horizontal movement, is contained in a spring loaded C-clamp frame which includes means for vertical movement.

United States Patent 1191 Olson et al.

PROBING DEVICE FOR MICROCIRCQITS Inventors: Jack Edward Olson, 1633South Yukon St., Lakewood; Guy G. Catalano, 3910 South Kalamath,Englewood, both of Colo.

Filed: Nov. 23, 1970 Appl. No.: 91,652

US. Cl. 74/102, 324/158 F, 324/158 P Int. Cl. F1611 21/44 Field ofSearch 74/25, 99, 102;

33/1 M; 339/75 R; 324/158 F, 158 P References Cited UNITED STATESPATENTS 10/1961 Bycer et a]. 33/1 M X June 26, 1973 3,551,807 12/1970Kubschenko et al 324/158 P 3,437,929 4/1969 Glenn 324/158 P PrimaryExaminer-William H. Schultz Attorney-Richard D. Law

[57] ABSTRACT A table supporting a three dimensional movement probemounted on roller bearings for two dimensional horizontal movement, iscontained in a spring loaded C-clamp frame which includes means forvertical movement.

14 Claims, 7 Drawing Figures PAIENIEDauuzs I975 3.741.022

sum 1 or 2 INVENTORS JACK EDWARD OLSON GUY G. CATALANO ATTORNEYPAIENIEDJUIZB ms 3'. 741; 022

sum 2 or 2 I NVENTORS JACK EDWARD OLSON I GUY G. CATALANO 7 )8 AATTORNEY 1 PROBING DEVICE FOR MICROCIRCUITS Electronic circuits havingrelatively large components such as vacuum tubes, etc., are easilychecked at various circuit junctions by hand held probes connected toconventional instruments as an oscilloscope. Of course, such probes maybe used in conjunction with other electrical test apparatus such asammeters, ohmmeters, and inductance measuring devices, etc. However,when the circuit is reduced to microminiaturize size, a hand-held probeis no longer feasable. It is extremely difficult to hand-hold a finelypointed needle at a delicate circuit junction; not only may inaccuratereadings result, but a slip or exertion of too much pressure coulddamage an expensive chip circuit. And, in many cases the part to betested is not visible to the unaided eye and very small movements of theprobe are necessary.

In the prior art devices are known whereby a thin needle probe extendingfrom a supporting structure may be remotely controlled. The typicalprobe is a complex arrangement of delicate springs, levers, hinges andpivots. Such arrangements usually exhibit backlash, i.e., movement ofthe controls does not produce exact predictable movement of the probe,so that precision is lost. Such devices must be very carefully handledat all times as a severe jolting may cause the probing instrument tolose its sensitivity. Further, delicate parts may quickly malfunctiondue to mechanical wear, or spring tensions may change with use, and thedevice thereby requires frequent maintenance or adjustment. In manyinstances, particularly with modular wafers, many such probes need to bepositioned at various points about a miniature electronic circuit inorder to make the necessary measurements. Size is, thus, an importantcriteria.

In general, the device of the invention provides mounting andpositioning structure for probes to test the electronic components ofminiature or microminiature circuits. The device provides controlledneedle positioning in three dimensions, i.e., in the X, Y and Zdirections of a rectangular coordinate system. The moving partsgenerally comprise plates sliding parallel to one another onwear-resistant race-fitted bearings. Movement of a joy stick controlaccurately positions the needle probe with negligable backlash.

An important object of the present invention is to provide a ruggedlyconstructed precision probe device.

A further object is to provide a probe device wherein manual controlmovement produces exact, predictable probe movement.

Still another object of the invention is to provide a probe devicewherein wear and adjustments are minimized.

Yet another object of the invention is to provide a probe deviceconveniently used with miniature'circuits.

A still further object of the invention is to provide a device whereby adepending probe may be positioned in three dimensions, along X, Y and Zaxes.

An additional object of the invention is to provide a probe devicewherein the probe needle is easily replaced.

Another additional object of the present invention is to provide a probedevice having such configuration that a large number of such devices maybe positioned circumferentially around a small circuit.

These and other objects and advantages of the present invention may bereadily ascertained from the following description and appendedillustrations in which:

FIG. 1 is a side elevational view of one form of a probe supportaccording to the invention;

FIG. 2 is a top plan view of the device of FIG. 1;

FIG. 3 is a perspective view of another modified form of probe supportaccording to the invention;

FIG. 4 is an end elevational view of the device of FIG.

FIG. 5 is an exploded view of the components of a further modified probesupport according to the invention;

FIG. 6 is a perspective view of the probe support of FIG. 5 in assembledcondition including a mounted probe thereon; and

FIG. 7 is a side elevational view of the device of FIG. 6, in largerdetail, showing the positioning of the components thereof.

In the device illustrated in FIGS. 1 and 2 a spring loaded C-clamp orC-frame 10 secures a probe support or X, Y, Z table 12 on a ball bearingstack. The table has lateral grooves 14and 15 extending across its widthin the vicinity of C-frame 10. Ball bearings 18 and 19 are arranged toride in the grooves 14 and 15 to permit the table 12 to move laterallyof the C-frame. Generally four spaced balls are used for uniform supportof table 12. A bearing positioning plate 20 secures the four balls inposition under the table 12. A middle ball support plate 22 includeslateral grooves 24 and 25, on its upper surface, which extends in thesame direction as the grooves 14 and 15 in the table 12. This permitsthe upper balls to support the table for movement laterally of theC-frame 10. On the lower side of the plate 22 two longitudinal grooves26 and 27 (at to the grooves on the upper side) accommodating balls 30and 31 to permit the upper stack members and table 12 to movelongitudinally of the C-frame,- and the balls ride in grooves 33 and 34in the bottom part of the C-frame 10. In this case three, four or fiveballs may be used in the registered grooves of plate 22 and the bottomof the C-frame. The movable stack is secured in position by the springaction of the C-frame 10 bearing against a ball .bearing 35, resting onthe top of plate 12 in a tight friction engagement. The ball 35 issecured in a recess 36 in the upper leg of C-frame 10. A joy stickcontrol lever 37 extends through an opening 39 in the top of the C-frameand is secured to the ball 35 to cause rotation of the ball 35 andthereby movement of the table 12. The stick may be moved 360 forcomplete circular movement of the table end. 1

The table 12 is moved in horizontal plane by movement of the joy stick37 with the ball bearings mounted in the various grooves, permittingfree movement of the table along X and Y axes which lie in the sameplane. The spring action of the C-frame 10 maintains the components intight engagement, but the balls mounted in the grooves permit movementof the table, on rotation of the ball 35, without any extraneousmovement or backlash. For a unit having an overall length of about 4 Ainches, and with a joy stick upper tip travel of about 1 inches a motionreduction of 9 to l is acquired permitting a probe movement within aboutthree-tenths of an inch diameter circle. The height of the probe above abase plane may be easily adjusted by means of wedges, cams or the likeplaced under the forward edge of the C-frame 10. A probe may be mountedon the small extended end of the table 12 in any convenient manner or asmay be desired. One form of probe mounting is shown in FIG. 7, describedbelow.

In a modified form of the probe support of the invention shown in FIGS.3 and 4, a spring C-frame is pivotally mounted by a pivot pin 41 in aU-shaped frame 42. The pivot pin may be a pin extending from one leg tothe other leg of the U-shaped support frame or may be a pin secured tothe C-frame 40 as may be desired or the pivotal connection may be a pinsecured to each side of the U-frame providing a point bearing in socketsin the C-frame, or other desired configuration. A three dimensionalprobe support table 43 is mounted on a ball and plate stack, shown ingeneral by numeral 44, similar to the stack illustrated in FIG. 1,including the grooves in the various plates for permitting lateralmovement of the table 43 in the C-frame 40. A ball 45 frictionallybearing on the table 43 causes movement of the table 43 on movement ofthe joy stick 46, as explained for the device of FIG. 1 above. Verticalmovement of the table 43 in the U-frame 42 is provided by means of apair of eccentrics 48 mounted on each side thereof by pivot pin 49extending through the U-frame. A cam 49a secured to the pin 49 below theC-frame 40 is rotated by rotation of eccentrics 48 against the bottom ofthe C-frame to provide vertical movement of the C-frame 40 around itspivot pin 41 in the U-frame 42. This provides for three dimensionalmovement of the probe support table 43.

In the device illustrated in FIGS. 5, 6 and 7, a C- frame is pivotallysecured to a base to provide a vertical adjustment for the probe supporttable. The C- frame 55 arranged'to provide spring tension on containedunits includes a pair of aligned holes 56 and 57 adjacent the ends ofthe legs thereof. A probe support or X, Y, 2 table 58 is provided with ahole 59 which is arranged to align with the holes in the C-frame. On thebottom of the table 58 areprovided lateral grooves 60 and 61 providinglateral ball races for the table. A bearing retaining plate 63 isprovided with ball retaining holes 64, 65 and 66 for retaining ballbearings that ride in the ball races 60 and 61, for example, balls 68and 69. The races 60 and 61 provide for movement of the table in the Yaxis. Plate 70 provided with grooves 71 and 72 thereon align withgrooves 60 and 61 and provide the Y'axis motion. Grooves 73, 74 and 75on the bottom thereof align with grooves 88, 89, and 90 on the bottomleg of the C-frame providing movement of stack in the X axis. Plate 63is provided with a hole 67 arranged to mate with the holes in theC-frame and the table, and the plate 70 is provided with a hole 77 formating with these holes. Retainer plate 80 is provided with ballretaining holes 81, 82 and 83 for retaining balls such as balls 84 and85 which are arranged to ride in the ball races 73, 74 and 75 and matingraces 88, 89 and 90. A hole 85 in the middle of plate 80 is arranged tomate with the other holes in the C-frame and plates. The longitudinalgrooves 88, 89 and 90 in the top of the bottom leg of the C-frameprovide the ball races for the X axis under the retainer plate 80, withthe balls 84 and 85 riding in the ball race grooves in the C-frame. Aretaining ball 92 attached to handle 93 secures the assembly in theC-frame in the manner described for in FIG. 1. A base plate is securedat one end by means of a rivets 108 to the bottom of the C-frame. Athreaded stud 101 extending through an opening 102 engages a femalescrew 103 extending through the openings in the stack and C-frame', towhich is attached a control knob 104. A hinge and spring plate 105 is,also, secured by rivets to the bottom of the C-frame to provide movementalong the Z axis on rotation of the control knob 104 which moves thefemale screw in relation to the threaded stud and thereby providesmovement of the C-frame in relation to the base frame 100.

With the arrangement of FIGS. 5, 6 and 7 the base plate sits on asupporting surface with a probe mounted adjacent a wafer circuit, and byrotating the control knob 104 and moving the joy stick control 93, theprobe may be moved in any position desired.

A probe is secured in a holder 111 which in turn is mounted in a base112 attached to the end of the X, Y, Z table 58. A wire or electricallead may then be attached to the probe 111 and passed back along theunit for connection to an instrument. By making the base 112 ofnon-conductive material the probe is isolated from the support table toprevent conductance of the current of the circuit to thesupport-mechanism.

Various types of base mechanisms may be used to support the C-frame. Auseful base is one having a magnet incorporated in it for adhering to aparamagnetic support surface. This provides quick placement of the probesupport and insures relatively immobility during use.

We claim:

1. A multidirectional movement probe support comprising:

a. a C-frame of resilient material providing spring action between itslegs; l

b. probe support table means positioned between said legs of saidC-frame and extending therefrom;

c. laterally and longitudinal movable means adjacent said table meanspositioned between said legs of said C-frame;

d. friction drive means bearing on said table means and one leg of said'C-frame whereby said table means and said movable meansare retainedtogether by spring biased action of said legs of said C-frarne;

e. means extending through said one leg of said C- frame for moving saidfriction drive means bearing on said table means and thereby moving saidtable means; and

f. means for moving one end of said C-frame vertically and therebymoving said table means in a vertical path.

2. A multidirectional movement probe support according to claim 1wherein said laterally and longitudinal movable means includes a seriesof ball bearings and bearing retainers means for free lateral andlongitudinal movement of said probe support table.

3. A multidirectional movement probe support according to claim 2wherein said series of ball bearings are formed in two sets, and one setis arranged in lateral bearing race grooves and the other set isarranged in longitudinal grooves in said bearing retainer means.

4. A multidirectional movement probe support according to claim 1wherein said friction drive means bearing on said table means is anenlarged ball bearing frictionally engaging said probe support table.

5. A multidirectional movement probe support according to claim 4wherein said enlarged ball bearing is mounted in a mating recess in saidone leg of said C- frame.

6. A multidirectional movement probe support according to claim 4wherein said means extending through said one leg of said C-frame is ajoy stick secured to said enlarged ball bearing providing completecircular movement in a plane of any point on said table means.

7 7. A multidirectional movement probe support according to claim 6wherein said joy stick movement is transmitted to said table means at afixed ratio of movement reduction.

8. A multidirectional movement probe support according to claim 7wherein said fixed ratio of movement reduction is in a range of 5:1 to20:1.

9. A multidirectional movement probe support according to claim 1wherein said means for moving said C-frame in a vertical path includesbase means pivotally secured to said C-frame, and means to providevertical pivotal movement of said C-frame in said base means.

10. A multidirectional movement probe support according to claim 9wherein said means to provide pivotal movement includes extendable screwmeans extended through said C-framelegs said table means and saidlaterally and longitudinally movable means and spaced from the pivotalconnection between said C- frame and base means'for providing angulardisplacement of said C-frame in relation to said base means.

11. A multidirectional movement probe support according to claim 9wherein said base is hingedly mounted from one end to said C-fram, andspring means therebetween biases said members toward open position.

7 1 2. A multidirectional movement probe support comprising:

a. C-frame means; b. a stack .of at least two movable planar elements,

one of which includes means for supporting a probe mounted in saidC-frame means;

c. a set of ball bearings mounted between and spacing said at least twomovable planar elements apart;

d. guide means for said ball bearings associated with said at least twomovable planar elements permitting relative movement of said elements ina single direction on said ball bearings;

e. ball bearing means on either side of said two movable planar elementsbearing against said C-frame means and thereby securing said elementsand C- frame means in an assembly; and

f. guide means associated with said C-frame means and said either sideof said movable planar elements permitting movement of said two planarelements in a direction to the movement between said two planarelements.

13. A multidirectional movement probe support having at least a pair ofplanar elements movable relative to each other inone direction and bothmovable conjointly in a direction which is 90 to said one direction, andframe means securing said elements in an assembly, the improvement ofball means mounted between saidpair of planar elements and said framemeans frictionally engaging one said planar element and movable thereon,a depression in said frame means and said ball means rotatably mountedin said depression and retained in one position on said frame, wherebyrotative movement of said ball means'moves said planar elements.

14. A multidirectional movement probe support according to claim- 13wherein a joy stick is attached to said ball means providing means forrotation of said ball means and thereby movement of said pair of planarelements in 360 in a plane.

1. A multidirectional movement probe support comprising: a. a C-frame ofresilient material providing spring action between its legs; b. probesupport table means positioned between said legs of said C-frame andextending therefrom; c. laterally and longitudinal movable meansadjacent said table means positioned between said legs of said C-frame;d. friction drive means bearing on said table means and one leg of saidC-frame whereby said table means and said movable means are retainedtogether by spring biased action of said legs of said C-frame; e. meansextending through said one leg of said C-frame for moving said frictiondrive means bearing on said table means and thereby moving said tablemeans; and f. means for moving one end of said C-frame vertically andthereby moving said table means in a vertical path.
 2. Amultidirectional movement probe support according to claim 1 whereinsaid laterally and longitudinal movable means includes a series of ballbearings and bearing retainers means for free lateral and longitudinalmovement of said probe support table.
 3. A multidirectional movementprobe support according to claim 2 wherein said series of ball bearingsare formed in two sets, and one set is arranged in lateral bearing racegrooves and the other set is arranged in longitudinal grooves in saidbearing retainer means.
 4. A multidirectional movement probe supportaccording to claim 1 wherein said friction drive means bearing on saidtable means is an enlarged ball bearing frictionally engaging said probesupport table.
 5. A multidirectional movement probe support according toclaim 4 wherein said enlarged ball bearing is mounted in a mating recessin said one leg of said C-frame.
 6. A multidirectional movement probesupport according to claim 4 wherein said means extending through saidone leg of said C-frame is a joy stick secured to said enlarged ballbearing providing complete circular movement in a plane of any point onsaid table means.
 7. A multidirectional movement probe support accordingto claim 6 wherein said joy stick movement is transmitted to said tablemeans at a fixed ratio of movement reduction.
 8. A multidirectionalmovement probe support according to claim 7 wherein said fixed ratio ofmovement reduction is in a range of 5:1 to 20:1.
 9. A multidirectionalmovement probe support according to claim 1 wherein said means formoving said C-frame in a vertical path includes base means pivotallysecured to said C-frame, and means to provide vertical pivotal movementof said C-frame in said base means.
 10. A multidirectional movementprobe support according to claim 9 wherein said means to provide pivotalmovement includes extendable screw means extended through said C-framelegs said table means and said laterally and longitudinally movablemeans and spaced from the pivotal connection between said C-frame andbase means for providing angular displacement of said C-frame inrelation to said base means.
 11. A multidirectional movement probesupport according to claim 9 wherein said base is hingedly mounted fromone end to said C-frame, and spring means therebetween biases saidmembers toward open position.
 12. A multidirectional movement probesupport comprising: a. C-frame means; b. a stack of at least two movableplanar elements, one of which includes means for supportiNg a probemounted in said C-frame means; c. a set of ball bearings mounted betweenand spacing said at least two movable planar elements apart; d. guidemeans for said ball bearings associated with said at least two movableplanar elements permitting relative movement of said elements in asingle direction on said ball bearings; e. ball bearing means on eitherside of said two movable planar elements bearing against said C-framemeans and thereby securing said elements and C-frame means in anassembly; and f. guide means associated with said C-frame means and saideither side of said movable planar elements permitting movement of saidtwo planar elements in a direction 90* to the movement between said twoplanar elements.
 13. A multidirectional movement probe support having atleast a pair of planar elements movable relative to each other in onedirection and both movable conjointly in a direction which is 90* tosaid one direction, and frame means securing said elements in anassembly, the improvement of ball means mounted between said pair ofplanar elements and said frame means frictionally engaging one saidplanar element and movable thereon, a depression in said frame means andsaid ball means rotatably mounted in said depression and retained in oneposition on said frame, whereby rotative movement of said ball meansmoves said planar elements.
 14. A multidirectional movement probesupport according to claim 13 wherein a joy stick is attached to saidball means providing means for rotation of said ball means and therebymovement of said pair of planar elements in 360* in a plane.